Cushioning material



Dec. 15,1970 &AWATSON 3546322 CUSHIONING MATERIAL 3 Sheets-Sheet 1Original Filed Dec. 30, 1964 N n w INVENTOR GEORGE A. WATSON A'ITORNEYDec. 15, 1970 e. A. WATSON &546.722

CUSHIONING MATERIAL Original Filed Dec. 30, 1964 3 Sheets-Sheet 2INVENTOR GEORGE A. WATSON ATTORNEY D 1970 G. A. WATSON V 3,546,722

CUSHIONING MATERIAL 3 Sheets-Sheet i Original Filed Dec. 30, 1964ACTUATING 5 j INVENTOR 4 g GEORGE A; WATSON ATTOR Y Unted States PatentO "ice 3,546,722 CUSHIONING MATERIAL George A. Watson, Charlotte, N.C.,assignor to Celanese Corporation, New York, N.Y., a Corporation ofDelaware Application Dec. 30, 1964, Ser. No. 422,341, now Patent No.3,423,795, which is a continuation-in-part of applications Ser. No.382,018 and Ser. No. 382,263, both July 13, 1964. Divided and thisapplication July 22, 1968, Ser. No. 761,?:76

Int. Cl. A47q 9/00 U.S. CL 5-337 6 Claims ABSTRACT OF THE DISCLOSURE Apillow comprising a randomly crumbled cohesve web of deregisteredcontinuous substantially parallel filaments.

This is a division of Ser. No. 422,34l, filed Dec. 30, 1964, now U.S.Letters Patent, 3,423,795, filed Jan. 28, 1969, which patent is acontinuation-in-part application of application Ser. No. 382,0l8, filedJuly 13, 1964, now Pat. 3,328,850 and application Ser. No. 382,263,filed July 13, 1964, now abandoned.

This invention relates to the production of batts suitable forcushioning and relates more particularly to the production of pillowsfrom webs of parallel crimped continuous filaments.

A great many pillows are now stuffed with battings made of polyesterfibers, e.g. fibers of terephthalate polyesters such as polyethyleneterephthalate. Conventionally the stuffing is made from a mass ofcrimped staple fibers by a process in which one or more webs of thefibers are formed on a carding machine (after the usual preliminaryOperations of opening the bales of staple fiber and picking the openedmass to prepare it for carding). These webs, which are conventionallytermed card webs," are fed onto a continuously moving belt on -which thedesired thickness of batting is built up. Thus a number of cardingmachines may be employed to feed a corresponding number of card webs,one above the other, onto the belt, or a single carding machine may becoupled to a suitable cross-laying device to produce a cross-layed webof the desired thickness on the belt. The resulting batting which may,for example, be about 26 inches wide and which may wegh about 8 ouncesper square yard, is then torn along transverse lines suitably spacedalong its length to produce short batts, each containing enough stuffingmaterial for one pillow (e.g. about 20 ounces of stulfing material),after which each batt is rolled up and stufed ino the pillow ticking.

It is an object of this invention to provide a method and apparatus forproducing pillows from polyester filamentary material, which willproduce such pillows much more rapidly than is possiblewth theconventional process now employed, and which will produce pillows ofhigher quality and better properties than the conventional polyesterfiber-filled products.

Another object is the provision of novel batts suitable for cushioningand of new, comfortable, lightweight pillows.

Other objects of this invention will be apparent from the followingdetailed description and claims.

This application is a continuation-in-part of my earlier application382,263, of July 13, 1964, whose entire disclosure is heren incorporatedby reference.

In accordance with one aspect of this invention, pillows are producedfrom a tow of a great many crimped 3,546,722 Patented Dec. 15, 1970continuous polyester filaments by continuously deregistering the crimpsof the tow and thereby opening the tow, continuously spreading the towto form a continuous light cohesve web of parallel crimped filaments,continuously feeding said web against a barrier to fold and crumple theweb against the barrier, severing the resulting folded and crumpled massfrom the continuous web Upstream of said mass and stuffing said severedmass into a pillow ticking.

By the use of the process of this invention highly resilient pillows areproduced at extremely rapid rates at very low cost, using comparativelyinexpensve equipment. For example, from a single strand of tow it ispossible to produce easily six or more pillows per minute.

The pillows so produced from the lightweight webs are superior to thosemade by filling the pillow with battings formed from polyethyleneterephthalate staple fibers. The pillows keep their springiness andplumpness much longer in use and do not tend to felt and shrink eitherin use or in washing.

The opening and spreading of the two to form the cohesve web ispreferably etfected in the manner taught in the previously mentionedapplication of Watson, Ser. No. 382,263. The tow used is commonlysupplied in the form of a band of parallel crimped filaments packed in acompressed bale. The crimps in the individual filaments are in registryso that there are formed ridges and troughs of aligned crimps, runningtransverse to the direction of the filaments, across the tow. Often thetow has a fine crimp superimposed on a coarse crimp of much largeramplitude; for example a crimp of 12 crimps per inch superimposed on acrimp of much larger amplitude and of a frequency of about 3 crimps perinch. The crimping is conveniently etfected by the producer in a stuffercrimping zone of the usual type. If a particularly sharp crimp isdesired, the tow may be heated during crimping (eg. by means of steam incontact with the tow in the crimping zone).

The tow may be conveniently opened, to prepare it for the air spreadingsteps by subjecting it, while moving in a predetermined path, to adifierential grippng action between a plurality of points spaced fromone another both longitudinally and transversely of the path, so thatcertain laterally spaced sections of the tow are positively grippedrelative to other laterally spaced sections of the tow, alternating withthe said gripped sections, which are not gripped at all or are grippedat different relative points. In this manner there is produced, as afunction of the differential positive gripping of the tow, a relativeshifting of adjacent filaments longtudinally of the tow, whereby thecrimps are moved out of registry with one another. Preferably, althoughnot necessarily, the differential grippng action is such that a relativelateral displacement between adjacent filaments of the tow is alsoeflected, so that the combination of two transverse filament movementsbrings about the complete opening of the tow.

The differential gripping action may be achieved by the provision of atleast one pair of rolls, one of which is smooth-surfaced and the otherof which is grooved over its entire periphery; if desired there may be aplurality of such pairs of rolls arranged in tandem. On each groovedroll, the grooves and the ridges alternating therewith may extendobliquely or helically in opposte senses from its center to its opposteends. Thus, when the tow passes between the two rolls of any given pairof one grooved and one smooth-surfaced roll, some of the tow sectionsare gripped between the peaks of the ridges of the grooved roll and theouter perpheral surface of the opposed smooth-surfaced roll, while othersections of the tow which are at that time located in registry with thespaces between the ridges of the grooved roll are not gripped betweenthe latter and the smooth-surfaced roll. Generally only one roll of eachpair is positively driven while the other is yieldably biased toward itand rotates due to the passing of the tow between the rolls.

Merely by way of example, the foregoing tow opening apparatus may be ofthe type disclosed in Canadian Pat. 674,101 (corresponding to acopending U.S. patent application Ser. No. 15 1,900, filed Nov. 13,1961, in the names of D. T. Dunlap and R. E. St. Pierre and assigned tothe same assignee as the instant application). To the extent necessary,therefore, the disclosure of the Canadian patent and Dunlap et al.application are incorporated herein by reference.

In the preferred method of spreading the tow is passed through an airspreader in which the moving tow, in fiattened condition, is confinedbetween parallel walls while streams of air or other suitable gas aredirected at the tow across its full width. Advantageously, the airspreading is effected in a plurality of stages in each of which the towis spread to a greater width than in the preceding stage. For bestresults the tow in any one stage is isolated from the effect of thefollowing stages as by passing the tow between stages firmly in contactwith a surface moving at a controlled rate, e.g. around and between apair of driven nip-defining rolls.

By air spreading it is possible to spread the tow readily, and veryevenly, to great widths to produce webs of extreme fineness, such aswebs containing less than about 500, e.g. 100 filaments per inch ofwidth, and in which the average air space per fil is appreciably greaterthan the diameter of the filaments. The average air space per fil is theaverage space between the filaments of the. web measured on a line inthe plane of the web, perpendicular to the longitudinal direction of thefilaments of the web, said space being calculated on the assumption thatall the filaments are arranged in a single plane, with no filamentscrossing other filaments. It may be calculated simply from a knowledgeof the average diameter of the filaments (D the width (w) of thesubstantially uniform web and the number of filaments (n) in said width,according to the formula: Average Air Space Per Fil=(w-nD --r.

In the preferred forms of the invention, the average air space per filis a plurality of times (e.g. five ten or more times) as great as theaverage lament diameter. Such webs may have densities well below oneounce per square yard, e.g. to %i or /2 ounce per square yard.

The air spreaders themselves advantageously have airdelivery slits orother suitable openings in one or both of the parallel walls betweenwhich the tow passes, said slits leading from a plenum chamber suppliedwith air at constant pressure. In one highly eifective Constructionthere are a series of slits, each running in a direction transverse tothe direction of movement of the tow and so arranged that all portionsof the tow are subjected to the air streams from said slits.Surprisingly it has been found that even when the width of the airspreader is 8 feet or more, the tow spreads uniformly and the outeredges of the tow, where the resistance to the air would be expected tobe less, attain substantially the same density as the control portionsof the tow.

In cross-section the air-delivery slits are preferably tapered,narrowing toward their outlets. The tapering may be symmetrical about anaxs perpendicular to the face of the web so that the air is blownstraight at said face, or the slits may be inclined so that the airimparts a forward or backward force to the moving tow.

The pressure in the plenum chamber may vary, one suitable range beingabout 1 to p.s.i.g.; higher pressures may be used, e.g. 100` p.s.i.g.but these. are economically wasteful. The pressure in the tow-confiningzone, between the parallel walls, is believed to be a little less thanatmospheric. When the air is blown straight at the face of the web, theair generally leaves the tow-confining zone from both ends of said zone.Surprisingly little air is needed to expand the tow. Despite thefineness of the webs, the walls of the tow-confining zones of the airspreaders need not 'be correspondingly close together; thus very goodresults have been obtained with towconfining slots inch in width.

In the early stages of spreading the tow web shows striations; that is,there are alternating narrow zones of high fiber density (in terms ofthe number of filaments per unit of web width) and low fiber density(i.e. visible lean portions) running generally lengthwse of the tow web,but at a slight angle (e.g. 2) to the precise lengthwise direction. Thenumber of such striations corresponds to the number of lands and grooveson the threaded roll engaged by the tow. I have found that an additionalstage or stages of air spreading, instead of accentuating thesestriations, elimnates them to a large extent, and that the striationsmay be removed by permitting the lightweight web to relax, after leavingthe last stage of spreading, The web is generally under a slight tensionduring its passage through the air spreaders, such tension beinginsufiicient to remove the crimp in the filaments; on relaxation, thecrimp in the filaments increases but the width of the web remains thesame. The relaxed webs are quite unform, but often do have some areas ofvisibly varying fiber density; the uniformity of the latter products is,however,

very much greater than that of the commercially uniform card webs ofstaple fibers produced on the most modern carding equipment.

In the fine webs of this invention all the. continuous filaments run inthe same general direction, lengthwise of the web. However, when onedoes not look at the whole of the long length of any particularfilament, but looks instead at the individual crimps thereof, it will beseen that most portions of the filament do not run in this generallengthwise direction but instead zigzag back and forth across suchgeneral direction. The amplitude of the crimps is such that, for anyparticular filament, the portion of the crimp at one side (hereaftertermed the crest of the crimp) overlaps one or more neighboringfilaments while the portion of the crimp at the other side (hereaftertermed the "Valley" of the crimp) overlaps one or more of itsneighboring filaments on said other side. This overlap helps to give thewebs their cohesiveness. For example, the filaments in the web may havea crimp whose amplitude (from a median line running in the samedirection as the filament) is in the range of about to %e inch, saidamplitude being measured from said median line to the top of a crest, orto the bottom of a Valley. Since there may, for example, be severalhundred filaments per inch of web width and since the crimps are not inregistry there will be considerable overlapping of filaments in the web.

When one turns from an examination of the crimps and takes a somewhatlarger, though still relatively short, View of the portion of anyparticular lament which contains several crimps, and which may be forexample /2 inch to several inches long, it will be found that theseportions are not perfectly parallel to the longitudinal direction of theweb, but make small angles therewith, which angles change in directionand magnitude along the length of the filament; generally these anglesare less than 20, although for very short portions (e.g. /2 inch long)the angle may be larger at times.

It is believed that the overlapping of the crimps and the overlappingdue to the presence of the angularly disposed short portions, justdescribed, contribute to the cohesiveness of the web so that, despiteits fineness, it can be readily handled as a unitary structure. Thedegree to which the individual filaments meander by virtue of thepresence of said crimps and angularly disposed short portions is not,however, very great; typically, the ratio of the straightened lengths ofthe individual filaments to the lengths of the same laments in the webis less than about 1 /2 :1 and, preferably, greater than 1.1:1, e g.about 1.2:1 to 1.4:1. This ratio may be measured by cutting apredetermined length of the web, removing the individual laments of thecut portion and measuring their lengths while under a tension justsufficient to remove the crimp; the results are then expressed as theratio between the measured lengths of the individual laments and saidpredetermined cut length.

In specifying denier per filament and total denier, the number givenherein, with respect to tows and webs, is the denier for the lamentsprior to crimping, i.e. the weight of 9000 meters of straight laments;the weight of 9000 meters of crimped, unstraightened laments or tow willnaturally be greater than these values.

Advantageously, the webs are spread to such an eXtent that when furtherair spreading is attempted, while the length of the web is keptconstant, the web strongly resists such spreading and returns to itsprevious width. That is, if a graph is plotted relating the air pressurein the spreader, as ordinate, to the degree of lateral spreading of themoving web, it is found that there is substantially no additionalpressure needed to effect spreading up to a certain width, after whichthe air pressure required rises sharply. The web density at which thissharp change occurs is termed herein the Potential Web Density. ThisPotential Web Density will vary depending on the type of tow which isemployed and particularly on the degree of intermingling and crossingover of the tow laments. In general, the optimum tows have Potential WebDensities below about 1 ounce per square yard, preferably less thanabout /2 ounch per square yard. Surprisingly, webs of such densitieshave been found to be easily handled and to maintain their unity withoutdisintegration or splitting during ordinary handling, folding, etc.

In the work on this invention, it has been found that when battings aremade of successve layers of spread webs, the battings made from thosewebs whose actual web densities are below about 1 ounce per square yardhave superior strength and may be handled much more readily withoutdanger of shifting of the layers than battings of the same total weightmade from webs of greater densities. In addition, per unit of weight,the battings composed of the low density webs are thicker and moreresilient than battings made up of webs of higher density. In general,it is most desirable to use a web whose actual density is less thanpreferably less than 7 times the Potential Web Density. As will be seenfrom the examples, however, excellent pillows may be made using webs ofhigher densities. Incidentally, the battings made by depositingsuccessive layers of the lightweight webs are very much more coherentthan battings made by similarly lapping card webs of staple fibers. Inthe drawings:

FIG. l is a schematic view of a tow-opening and spreading process;

FIG. 2 is a cross-sectional View of an air spreader;

FIG. 3 is a view showing the arrangement of the openings of the airspreader;

FIG. 4 is another view showing the overall arrangement of the slits ofthe air spreader;

FIG. 5 is a view similar to FIG. 4, but showing an alternativearrangement of the slits;

FIG. 6 is a schematic view showing a process for the production ofpillows; and

FIGS. 7, 8 and 9 are schematic views of other, preferred processes forthe manufacture of pillows,

FIG. 10 is a side View of a device for measuring the electricalresistance of fibers.

The following examples illustrate the invention further.

EXAMPLE 1 The apparatus shown in FIG. 1 is used to open and spread aband of crimped polyethylene terephthalate tow having a total denier of128,000 and made up of 5 denier continuous laments, said laments having12 crimps per inch and a "percent crimp of about 60%. Percent crimp asused herein is where Lc is the length of any predetermined portion of atow or web and Ls is the average length of the laments of saidpredetermined portion when under a tension just suflicient to remove thecrimp.

The tow band 1 is drawn from the bale 2 through a banding jet 3comprising a cylinder 4, having a slit running lengthwise of thecylinder at its highest point, and a curved baffle member 6 parallel to,and spaced f inch from, the adjacent surface of said cylinder, so thatthe tow band 1 passes between said baffle member 6 and said cylinder 4.Air under pressure of 3 p.s.i.g. is supplied to the interior of thecylinder 4 and emerges as a stream from the slit of said cylinder, theslit being cut at an angle such that the air stream has a Component in adirection opposing the forward motion of the stream, there being anangle of about 30 between the stream emerging from the slit and a planetangent to the cylinder at the point of emergence. The tow band 1, nowabout 8 inches wide, passes around stationary tensioning bars 7, 8 tohelp smooth and uniformly pretension said band, said bars beingadjustably mounted, so that their angle to the horizontal may be varied,to adjust the position of the band on the equipment, such as rolls, withwhich the band comes into contact downstream of said bars. After leavingthe bars 7, 8, the band passes into the nip between a pair ofrubber-surfaced rolls 9, 11 driven at a peripheral speed of 60 feet perminute and then passes horizontally to the nip between a rubber-surfacedroll 12 and a threaded steel roll 13, driven at a peripheral speed of102 feet per minute, said threaded roll having helical threads of 14turns per inch cut about inch deep into its outer surface. The towentering the nip between rolls 12, 13 is still about 8 inches wide. Fromthese rolls it passes still in the same horizontal plane to an airspreader 14 (see also FIGS. 2 and 3) having a tow-receving slot 16 whichis 24 inches wide and 4 inches long. The tow-receiving slot 16 isdefined by an upper wall 17 and a lower wall 18 spaced inch apart. Belowthe lower wall 18 is a plenum chamber 19 supplied with air under aconstant pressure of 3 p.s.i.g. from a suitable source (not shown) andcommunicating with the tow-receving slot 16 through air slits 21, each0.007 inch wide at their outlet ends and tapered to said outlets at anincluded angle of 45, said slits being each 5 inches long and soarranged (as shown in FIGS. 3 and 4) that the end of one slit isaligned, in the direction of movement of the tow, with the end of theadjacent slit, so that the air is supplied to the tow band across thefull 24-inch width of the slot 15. The slits are arranged at smallangles (e.g. about 5) to the line perpendicular to the direction ofmovement of the tow with the slits on opposite sides of the median lineof the spreader being mirror images, as shown in FIG. 4; it is foundthat when the slits are all parallel, and at an angle to saidperpendicular line, there is a tendency for the tow band to be turnedfrom its straight path by the action of the air, the band at one side ofsaid median line being retarded and at the other side being accelerated.Instead of angularly arranged slits there may also be employed slits 21a(FIG. 5) running perpendicular to the direction of movement ot' the towand in parallel rows, spaced with the end of a slit in one row aligned,in said direction of movement, with the end of a slit in the adjacentrow so that the air is supplied to the tow band across the full 24-inchwidth of the slot 16, without any substantial operative overlap of theslits.

The tow band diverges uniformly from its 8 inch width at rolls 12, 13 tothe full 24-inch width at the exit of spreader 14, the entrance of whichis located one foot from the nip of rolls 12, 13. The tow is pnlledthrough the spreader 14 by the action of a pair of rolls 26, 27, makingan S-wrap around these rolls; that is, passing 180 aroundrubber-surfaced roll 26 then passing through the nip between the rollsand then making another l80 wrap around a steel-surfaced roll 27. Thetow web keeps its 24-inch width during its travel to and around therolls 26, 27 which are driven at a peripheral speed of 61 feet perminute.

From the lower portion of roll 27 the tow then passes to the entrance ofair spreader 28 which is located 3 feet horizontally from, and about onefoot below, the level of the bottom of roll 27, so that the tow makes asmooth curve which is horizontal at the entrance of spreader 28. Thespreader 28 is of the same design as spreader 14, except that itstow-receiving slot is 50 inches wide, and it is operated under the sameair pressure as spreader 14. The tow web spreads uniformly in itshorizontal passage to spreader 28, at which it reaches its SO-inch widthand then maintains the same width during its passage to a pair of rolls29, 31, driven at a peripheral speed of 59 feet per minute, which serveto pull the web through the spreader 28. Roll 29 is rubber-surfacedwhile roll 31 is steel-surfaced; the top of roll 29 is on a level withthe tow-receiving slot of spreader 28 and below the bottom of roll 27.The tow makes an S-wrap about the rolls 29, 31, falling from the roll 31in a freely hanging shallow catenary 32 onto the horizontal movingsurface of a wide endless belt 33 driven at a speed of 55 feet perminute. An idler roll 34, mounted on lever arms 36 pivoted at 37,extends across the full width of the tow web on belt 33; this idler rollserves to bring the tow web into firm contact with the belt 33, todefine the shape and position of the catenary 32, and also to keep anyloose ends in the catenary portion from being drawn around the roll 31.The path of the belt is 2 feet below the bottom of roll 31 and the roll34 is mounted inches forward (in the direction of movement of the belt)of the center of roll 31. The web on belt 33 has a width of 50 inchesand a weight of 14 grams per square yard, and its percent crimp is aboutIn this example, the upper roll of each of the pairs of rolls is presseddownwardly, by any suitable loading device, and is driven by frictionalcontact with the tow on the lower roll of the pair, which lower roll isrotated by any suitable driving means (not shown).

A barrier 38 (FIG. 6) is placed just above belt 33, with the bottom ofthe barrier slidably resting on the belt. The lightweight web 39travelling with the belt piles up in a loosely folded and crumpled massagainst the barrier 38 which may, for example, be 10 inches high. Whenthe desired amount of web (e.g. 1% lbs.) has piled up against thebarrier, the Web is cut transversely upstream of the folded and crumpledmass as with a knife 40, and the mass of folded and crumpled web ispushed or pulled transversely off the belt 33 as by pusher 41 into asuitable hollow form or mold 42 and into a sacklike pillow ticking 43whose mouth is aligned with the outlet of said mold 42. When the freshlycut end of the web travelling with the belt 33 reaches the barrier, anew pile-up is begun and the action is repeated. The whole operation mayreadily be made automatic, since the web is supplied at a uniformcontrolled speed and at a uniform weight per unit of time. Thus, in oneform of apparatus, the operation of the knife and the pusher 41 arecontrolled by a suitable timed controller to operate substantiallysimultaneously at predetermined intervals, so that when a preset weightof the web has folded against the barrier the knife 40 is actuated tocut the web and the pusher is actuated to transfer the accumulated webto the mold 42. In this way highly resilient pillows may be producedcontinually at a very high rate from suitable stiff, resilientfilaments, such as filaments of terephthalate esters.

In another method, the barrier 38 is adapated to be raised when thedesired weight of crumpled web has accumulated and the web has beensevered, as previously 8 described. The accumulated mass then is carriedby the belt 33 to a pillow packing station (not shown) located at theturning point of said belt. The barrier is quickly lowered after themass of crumpled web has passed under it, so as to begin a new cycle.

EXAMPLE 2 (a) When the speeds of all rolls and of the belt are increasedto about 6 times the values given in Example 1 above (so that the speedof the rolls 29, 31 is yards per minute) substantially the same productis obtained. Surprisingly, despite the great increase the rate at whichthe web is produced, the total volume of air used and all otherconditions, are substantially unchanged.

(b) On increasing the speeds of the rolls and the belt to about 10 timesthe values given in Example 1 above (so that the speed of rolls 29, 31is 200 yards per minute) substantially the same product is obtained, andas in Example 2(a) above, the total volume of air consumed and all otherconditions remain substantially the same despite the tenfold increase inproducti vity.

EXAMPLE 3 This example llustrates the use of an apparatus whichfacilitates the handling of the crumpled mass during the cutting andstuffing Operations, while the web is fed to the crumpling and foldingzone at a high speed. As shown in FIG. 7, the opening and spreadingstops are the same as those of Example l except that the tow, afterleaving the roll 31, passes between a driven roll 51 and an idler roll52 and drops onto (and is permitted to relax on) a barrier 53 which, inthe embodiment shown in the drawing, is made up of a pair of doors 54,56 pivoted at their upper ends 57, 58 on parallel horizontal pivots 59,61, respectively. The doors are maintained in closed position, withtheir edges in contact, in any suitable manner as by means of hydraulicoperators 62, 63 which may also be actuated to move the doors to openposition. When the desired amount of spread tow has accumulated on thebarrier 53, the doors are opened for a very short interval and thefolded and crumpled mass is allowed to drop onto a slowly moving endlessbelt 64 (moving at a speed of, for example, about 50 to 60 feet perminute). The doors are then closed again and the tail of tow extendingup from the crumpled mass is cut, as by the filamentfusing action of anelectrically heated wire 66 moving across this upwardly extending tail.The wire 66 may be mounted, as shown, on one of the doors 56 formovement with that door or may be separately mounted and actuated eitherindependently or by movement of the door. The door actuators may becontrolled by a valve 67 actuated by any suitable intermittentlyOperating mechanism 68, preferably one which is responsive to the amountof tow deposited ou the barrier 53; thus the mechanism may be directlyresponsive to the weight of tow accumulated on the barrier, or it may beoperati'vely connected to one of the feed rolls 51, 52 so that itoperates when a given length of tow, as measured by the number ofrevolutions of these rolls, has been supplied to the barrier, or it maybe connected to a suitable timer. The individual masses of tow depositedon the slowly moving belt may be deposited in a collection trough 70 andmanually or automatically stuffed into a pillow ticking, as in themanner shown in FIG. 6.

It will be seen that, in contrast to Example 1, the stuffing and cuttingOperations of Example 3 are carried out on a material which is notmoving rapidly, and that the tow may be spread and delivered to thebarrier at very high rates (such as speeds of about 300 to 600 f.p.m.)without increasing the difficulty of the cutting and stufiingOperations.

Another method of achieving an effect similar to that shown in FIG. 7 isillustrated in FIG. 8 in which the doors 54, 56 are kept open while themajor portion of the web making up the pillow filling passes, throughthe open doors, onto the slowly moving belt 64 where, because the speedof the belt is less than that of the web, the Web forms a crinkled,flufy layer on the belt. In this embodiment, a movable barrier 71, likebarrier 38, is placed across the belt 64 with the bottom of the barrier71 slidably resting on the belt, so that the web, travelling with thebelt as a flulfy layer, piles up in a loosely folded and crumpled massagainst the barrier. As in the embodiment shown in FIG. 7, the width ofbelt 64 is at least equal to the width of the web falling from the rolls51, 52 so that the Web is uniformly deposited across the width of thebelt; this is not essential, however, since for example suitable guidesfor decreasing the width of the web before it engages the belt may beprovided. When the desired amount of web material has piled up againstthe barrier 71, the doors 54, 56 are closed so that the web is cuttransversely by the action of the heated wire 66. The barrier 71 is thenraised momentarily, permitting the crumpled mass to move With the belt64 to a suitable pillow-stuffing station, and the doors 54, 56 areopened, permitting 'the small mass of web material accumulated on thedoors to fall onto the belt 64 and pile up, with the subsequentlydelivered web, on the barrier 71, in the next identical cycle ofoperation. In the modification shown in FIG. 8, less headroom isrequired than is needed for that of FIG. 7, since space need not beprovided for a large fluffy mass of crumpled web material above thedoors.

Another arrangement, shown in FIG. 9, is similar to that of FIG. 8. Herethe positions of the feed rolls (51 and 52 in FIG. 8) are changed, sothat the web now makes greater contact with the feed rolls, numbered 81and 82 in FIG. 9; this gives better control of the web feed rate. Whenthe distance between the feed rolls and the doors 57, 58 is relativelyshort (e.g. 4-5 feet or less), the weight of the short length of themoving web hanging from the feed rolls is sometimes insuicient to keepthe filmy web from drifting sideward against one of the feed rolls,starting an undesired roll wrap. To prevent this, an air control device,comprising parallel tubes 83, 84, one on each side of the web, is placedbelow the feed rolls. Air under low pressure is supplied to the tubes83, 84, which have spaced perforations, facing the tow band, arranged todirect gentle streams of air downwardly toward the web (eg. at an angleof 45 to the horizontal) along the whole width of the web.

The steps of crumpling and of stuffing the crumpled mass into a pillowticking may be performed substantially simultaneously, as by feeding thespread tow directly into the ticking. Thus the spread tow web may bepassed down into a guide tube, e.g. a tube of downwardly taperingconical shape in which the moving tow folds longitudinally, and theninto the ticking. Here the tow may be crumpled against the bottom of theticking, which serves as the barrier, or an intermediate intermittentlymovable barrier may be placed just above the ticking.

In the practice of this invention, high speed operation is facilitatedby omittng devices that produce regular folds. The folded and crumpledmass so produced has a random configuration. In this mass the lengths ofspread tow between folds may, for example, be in the range of about l to4 inches.

In the finished pillows, the Weight of crumpled web material Willdepend, of course, on the desired resilience and size of the pillow. Forpillows of the conventional sizes (having an area of about 500 to 600square inches, e.g. a pillow whose dimensions are about 20" by 26") thedensity of the crumpled web is advantageously in the range of about /2to 1 /2 pounds per cubic foot before stuffing into tick.

According to another aspect of this invention, it has now been foundthat outstanding results are obtained by using filaments carrying ahydrophobic silicone finish containing little or no antistatic agent, asdescribed in my copendng application Ser. No. 382,018 filed July 13,

1964, whose entire disclosure is hereby incorporated by reference. Notonly does the use of such a finish enhance the spreading action in theproduction of the continuous light cohesive webs, but it results in theproduction of pillows of especially good resiliency. The filamentscarrying the silicone finish containing little or no antistatic agent(eg. at most about 0.1% weight percent, preferably less than 0.05%, ofantistatic agent based on the weight of the fiber) have very slicksurfaces and there is very little friction between filament surfaces, sothat the filaments can slide past each other freely. Thus there islittle, if any, frictional interference with the inherent resilientrecovery properties of the individual filaments. The pillows stufiedwith the filaments are also easily washed, and dry rapidly to return totheir original highly resilient condition. In conventional polyesterstaple fiber filled pillows the staple fibers carry a considerableproportion of a relatively tacky antistatic agent which increases thefiber-to-fiber friction and, I have found, decreases the resiliency ofthe pillow. The presence of anti static agent is, however, essentialwhen the staple fibers are employed in order that these fibers may behandled readily in the usual preparatory Operations, eg. picking andcarding. It will thus be seen that, in accordance With this aspect ofthe invention, an inherently high static fiber, such as polyethyleneterephthalate, which ordinarily must be given an antistatic finish topermit it to be handled, is here given a finish which, in contrast,increases the static properties of the fiber.

The electrostatic properties of the fiber may be expressed in terms ofthe electrical resistance of the fiber. The high static fibers of thisinvention preferably have resistances, measured in the manner describedbelow, of at least 12 logohms, preferably at least 14 logohms and mostpreferably at least 15 logohms. A typical siliconecoated polyethyleneterephthalate fiber highly suitable for the practice of this inventionhas a resistance of 15.3 logohms; as used herein the electricalresistance of the fiber is the value measured by the following method: A1.7 gram specimen of tow l0 inches long is placed on a sample holderillustrated in FIG. 10 composed of a series of 5 horizontal knife-edgedbars 91, supported parallel to each other along a circular arc betweeninsulated holders so that each knife edge is 1.3 inches from itsneighboring edge. The specimen 92 is draped over these bars in contactwith the knife edges, one end of the specimen being held in a fixedclamp 93 and the other end being clamped to a 171 gram weight 94 whichis supported only by the specimen. The specimen is clasped in such afashion that its width, as draped over the bars 91, is one inch. Avoltage of volts D.C. is applied successively across each pair ofadjacent bars and the current flowing through the tow in response tothat voltage is meas ured. The five readings of current are averaged andthe average resistance of the tow sections between knife sections isthus determined in accordance with Ohrns law average current) Allmeasurements are made at 70 F. and 40% R.H., with tow that has beenpreconditioned at 70 F. and 40% R.H. for 24 hours.

Preferably there is a tough, fiexible, hydrophobic film of siliconeresin around each individual fiber. The silicone is desirably applied tothe filaments during their early stages of processing and before theband of tow is crimped. This may be done Conveniently by passing thefilaments through an aqueous emulsion of a relatively low molecularweight curable liquid silicone prior to the step of crimping thefilaments and, in the case of materials which, like polyethyleneterephthalate, must be drawn to develop desirable tenacity andresistance to elongation, prior to the drawing operation.

A suitable silicone is readily made, for example, from the hydrolysis ofa major portion of an alkyl dichlorohydrogen silane and a minor portionof a dialkyl dichlorsilane. If desired, there may also be incorporated asmall amount of trialkyl chlorosilane (as a chain terminator) and asmall amount of alkyltrichlorosilane (to promote prcliminarycross-linking). All the alkyl groups are preferably methyl groups. Theuse of these starting reactants results in a relatively fluid siliconecontaining a major portion of methylhydrogenpolysiloxane and a minorportion of dimethylpolysiloxane.

The polymeric silicone, after it has been emulsified and the emulsionapplied to a filamentary material, can then be catalytically oxidized orcured so that the silane hydrogens are converted to additional siloxaneoxygen bridges, to further cross-link the silicone. The resultantcross-linked polymeric product is tough, hydrophobic, and highlylubricating; forming a flexible film around the surface of eachfilament.

It is convenient to first emulsify the silicone so as to form an aqueousemulsion of paste-like consistency. Any of the conventional siliconeemulsifying agents, e.g. trirnethylnonyl ether, can be used. The averageparticle size of the silicone polymer in this paste emulsion isgenerally from about 1 to 8 microns, and typically is about 5 microns.This paste is then incorporated into the finishing bath, along withCatalyst. The Catalyst compound used to promote further cross-linking ofthe silicone is of the conventional type used for silicone curing andgenerally is an organometallo compound or mixture thereof, and istypically an organometallo salt. Generally the metal portion of suchCatalyst compound is zinc, tin, aluminum,

zirconium, or the like. Suitable catalysts include Zinc acetate,aluminum octoate, Organic titanates, and mixtures thereof. As statedpreviously, such Catalyst promotes oxidation of the silane hydrogens toproduce additional siloxane oxygen linkages and thereby promote furthert cross-linking of the silicone polymer.

Generally the catalyst is maintained separate from the silicone emulsionuntil the finishing bath is to be prepared, and desirably is added asthe last Component to the finishing bath.

Desirably the weight ratio of silicone to metal Catalyst is from about 8to 1 to about 1 to 1. A more preferred range is from about 5 to 1 toabout 3 to 1. The aqueous composition applied to the filaments maycontain, for example, 1 to 5% of the silicone.

The proportion of silicone on the filaments is advantageously less than1%, preferably in the range of about 0.2 to 05%, based on the Weight ofthe filaments. The amount of any antistatic agent present should be lessthan /3, preferably less than /5 the weight of the silicone.

The crimping of the filaments carrying the silicone finish isadvantageously carried out in a stuffer crimper, which may be of thestandard stufiing box type in which the tow is forced into a narrowconfined zone, thus folding the filaments back and forth on themselvesin their passage through said zone. The tow in the crimper may carry awet film of the aqueous uncured silicone finishing composition, whichmay be subsequently cured by heat treatment of the crimped tow while thelatter is maintained in a relaxed condition, e.g. at a temperature above100 C., for example, 130-180 C. Curing of the silicone may also beeffected prior to crimping, as by passing the filaments carrying theuncured silicone 'finish through a heated drawing zone.

The invention finds its greatest utility in the production of pillowsfrom tows whose filaments are of polyethylene terephthalate. It will beunderstood that it is within the broad scope of the invention to carryit out with other tows, such as those made of other polyesters (eg. thepolyesters of terephthalic acid and other glycols such as dimethylolcyclohexane), luear superpolyamides (such as nylon 6 or nylon 6,6),polyacrylonitrile and copolymers of acrylonitrile, olefinic polymers andcopolymers, e.g. isotactie polypropylene, secondary cellulose acetate(of the usual acetyl content, eng. about 54-55% calculated as aceticacid), other Organic derivatives of cellulose such as esters and/orethers of cellulose, for example cellulose propionate and celluloseacetate propionate or the like, highly esterified cellulose containingless than 0.29 free hydroxyl groups per anhydroglucose unit such ascellulose triacetate, rayon (regenerated cellulose). The number of'filaments of the starting tow can vary within wide limits and may rangeup to as high as 1,000,000, with a denier per filament as high as 25,e.g. 1 to 20. The number of crimps per inch of tow may range up to ashigh as about 80, but for most end products to be described herein about3 to 50, preferably about 3 to 20, crimps per inch of starting tow arefound sufficient.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of this invention.

T he embodiments of the invention in which an ex clusive property orprivilege is claimed are defined as follows:

1. A pillow filled with a cohesive web of deregistered crimpedcontinuous substantially parallel filaments carrying a coatingconsisting essentially of a hydrophobic silicone, said coated filamentshaving an electrical resistance of at least 12 logohms.

2. A pillow as set forth in claim 1 in .which said filaments are ofterephthalate polyester and the crimps of the 'filaments of the weboverlap adjacent filaments of the web on both sides of said filaments.

3. A pillow as set forth in claim 1 in which said web is randomlycrumpled, said filaments are of terephthalate polyester and saidelectrical resistance is at least 15 logohms.

4. A pillow as set forth in claim 1 in which said filaments have a crimpamplitude of from about inch to 7 inch and a ratio of the straightenedlengths of individual filaments to the lengths of the same filaments inthe web of from about 1.1:1 to 1.521.

5. A pillow as set forth in claim 2 in which said filaments are ofpolyethylene terephthalate of a denier of about 1 /2 to 10, and said webis one which, before crumpling, has a weight of at most about 2 ouncesper yard, a width of at least about 24 inches and contains at leastabout 50,000 filaments, the density of crumpled web in said pillow beingabout /2 to 1 /2 pounds per cubic foot.

6. A pillow as set forth in claim 4 in which the ratio of thestraightened lengths of individual filaments to the lengths of the samefilaments in the web is from about 1.2:1to1.4:1.

References Cited UNITED STATES PATENTS 3,251,794 5/1966 Paliyenko 5-337X3,071,783 1/1963 Gamble i 5-337 3,156,016 11/1964 Dunlap et al. 19-66BOBBY R. GAY, Primary Examiner A. M. CALVERT, Assistant Examiner U.S.Cl. X.R. 5-345; 19-66

